uid=MCM,o=EDI,dc=edirepository,dc=org all public read STRM_MICROBIAL_BIOMASS Lydia Zeglin lzeglin@ksu.edu http://www.zeglinlab.com https://orcid.org/0000-0003-2907-0742 Diane McKnight diane.mcknight@colorado.edu https://orcid.org/0000-0002-4171-1533 McMurdo Dry Valleys LTER http://mcmlter.org/ Natalie Aranda Natalie.Aranda@colorado.edu https://orcid.org/0009-0005-4964-6085 field technician Renée Brown rfbrown@unm.edu https://orcid.org/0000-0002-4986-7663 data manager Mia Vanderwilt Mia.Vanderwilt@colorado.edu former field crew Joshua Darling joshua.darling@colorado.edu https://orcid.org/0000-0001-9074-4617 former field crew Nick Schulte Nicholas.Schulte@colorado.edu former field crew Tyler Kohler tyler.j.kohler@gmail.com https://orcid.org/0000-0001-5137-4844 associated researcher Breana Simmons bsimmons@ega.edu associated researcher 2025-10-13 English

As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, a systematic sampling program has been undertaken to monitor the glacial meltwater streams in that region. This dataset contains microbial biomass concentrations found in algal mats located in streams throughout the McMurdo Dry Valleys as well as in ponds of the nearby Cape Royds. Microbial mat biomass has been collected as part of the McMurdo LTER since the 1993-1994 field season and measured as ash-free dry mass (AFDM) and chlorophyll-a (Chl-a).

algae biomass chlorophyll chlorophyll a microbial biomass ponds stream ecology streams LTER Controlled Vocabulary algae Antarctic desert streams Antarctica ash free dry mass biomass chlorophyll mass McMurdo Dry Valleys microbial biomass microbial mat Station Keywords primary production LTER Core Areas

This data package is released under the Creative Commons Attribution 4.0 International License (CC BY 4.0; http://creativecommons.org/licenses/by/4.0/), which allows consumers (hereinafter referred to as “Data Users”) to freely reuse, redistribute, transform, or build on this work (even commercially) so long as appropriate credit is provided. Accordingly, Data Users are required to properly cite this data package in any publications or in the metadata of any derived products that result from its use (in whole or in part). A recommended citation is provided on the summary metadata page associated with this data package in the McMurdo Dry Valleys LTER Data Catalog (https://mcmlter.org/data), and a generic citation may be found on the summary metadata page in the repository where this data package was obtained. When these data contribute significantly to the contents of a publication, Data Users must also acknowledge that data were provided by the NSF-supported McMurdo Dry Valleys Long Term Ecological Research program (OPP-2224760). This data package has been released in the spirit of open scientific collaboration. Hence, Data Users are strongly encouraged to consider consultation, collaboration, and/or co-authorship (as appropriate) with the data package creator(s). Data Users should be aware these data may be actively used by others for ongoing research; thus, coordination may be necessary to prevent duplicate publication. Data Users should also recognize that misinterpretation of data may occur if they are used outside the context of the original study. Hence, Data Users are urged to contact the data package creator(s) if they have any questions regarding methodology or results. While substantial efforts are made to ensure the accuracy of this data package (with all its components), complete accuracy cannot be guaranteed. Periodic updates to this data package may occur, and it is the responsibility of Data Users to check for new versions. This data package is made available “as is” and comes with no warranty of accuracy or fitness for use. The creator(s) of this data package and the repository where these data were obtained shall not be liable for any damages resulting from misinterpretation, use, or misuse of these data. Finally, as a professional courtesy, we kindly request Data Users notify the primary contact referenced in the metadata when these data are used in the production of any derivative work or publication. Notification should include an explanation of how the data were used, along with a digital copy of the derived product(s). Thank you.

https://mcm.lternet.edu/content/algal-microbial-mat-biomass-measurements-mcmurdo-dry-valleys-and-cape-royds-antarctica-1994 1994-01-07 2025-02-01 20251013: Methods were updated to correct an error in the drying temperature, which was incorrectly listed as being 100 °C. The protocol is to dry the samples at 55 °C since nitrogen may be volatile at temperatures around 60 °C.The original iterations of the 'stream microbial biomass' data file were created by Tyler Kohler, Lee Stanish and Diane McKnight, and submitted to Inigo San Gil (the data manager) at the Institute of Arctic and Alpine Research (INSTAAR). For proper standardization in the database, the data was massaged into the fields strmgageid, collection date, etc. Entered in the database using Toad 4 Oracle from Dell inc (formerly own by Quest inc.) McMurdo Dry Valleys LTER Information Manager im@mcmlter.org McMurdo Dry Valleys LTER http://mcmlter.org/ McMurdo Dry Valleys LTER

Algal mats were sampled along transects established by the MCM LTER in early to mid-January as in Alger et al. (1997), and mats were identified as either orange, black, green, or red in color. Mats were collected using a brass cork borer (1.7 cm diameter) and placed into Whirlpack® bags containing stream water. In the laboratory, samples were de-watered on pre-combusted Whatman GF/C filters, wrapped in foil, and stored at -20°C. Prior to the year 2000, Chl-a samples were extracted in buffered acetone and analyzed spectrophotometrically using the trichromatic method. After 2000, Chl-a was extracted in buffered acetone and analyzed using a Turner Designs 10-AU field fluorometer. Both methods have been shown to produce comparable Chl-a results (Lorenzen and Jeffrey 1980). For AFDM analysis, samples were dried at 55 °C for 24 h, weighed, burned at 450 °C for 4 h and re-weighed, and then re-wetted and dried to determine mass loss due to hydration of sediments. Both Chl-a and AFDM analyses were performed at Crary Laboratory in McMurdo Station. Additional notes: AFDM for 2019-2020 season samples was conducted at CU Boulder in 2022. Samples collected during the 2020-2021 "Covid year" season were collected by a contractor and sent back to CU Boulder for analysis. Chl-a was analyzed on a UV Vis Spectrophotometer. Samples were kept in refrigeration for two months before Chl-a was analyzed. For AFDM analysis, samples were put directly into drying tins and were not placed on filters. In the 2022-2023 season, the protocol varied from the the typical protocol, which is to collect a sample of algal mat and dewater it with a combusted and pre-weighed filter. This filter is then a part of the sample when it is dried, combusted, and rewett. Inserting the filter after collection was overlooked and was realized at the rewetting step because the filter aids in rewetting the combusted mat. We made the decision to add the filter at this step in order to continue with the rewetting. We took note of the weight of the filter and subtracted it out as is usually done.

STREAMS_MICROBIAL_BIOMASS mcmlter-strm-microbial_biomass-20250225v2.csv 447180 1 1 \n column , " https://mcm.lternet.edu/sites/default/files/data/mcmlter-strm-microbial_biomass-20250225v2.csv DATASET_CODE Dataset code Code representing the data Object string Code representing the data Object STRMTRNSID Stream Transect ID Code representing stream transect identifier. Represents where sampling was conducted string Code representing stream transect identifier. Represents where sampling was conducted STREAM NAME Stream Name The name of the stream where sampling occurred string The name of the stream where sampling occurred SAMPLE NAME Sample Name A name that serves to identify the sample. This encodes the replicate number. string A name that serves to identify the sample. This encodes the replicate number. DATE_TIME Date Time Date/time of sample (McMurdo time) date MM/DD/YYYY hh24:mm AFDM (mg/cm2) Ash Free Dry Mass (milligrams per sq. centimeter) Ash Free Dry Mass in milligrams per square cm milligramsPerSquareCentimeter 0.01 real Null None given Chl-A (ug/cm2) Chlorophyl-A (ug/cm2) Chlorophyl-A density (concentration) microgramsPerSquareCentimeter 0.01 real Null None given MAT TYPE Mat Type Type of mat, by pigmentation or substrate string Type of mat, by pigmentation or substrate SEASON Season the season the study was conducted, as a year date YYYY COMMENTS Comments Remarkable comments string Remarkable comments